As Kalas and Xelha escape on a transport to Diadem the ticket man is stuck with some obviously unhappy imperial troops to deal with.
Liner Man: (in a meek and squeaky voice) Erm... The liner is underway!
When Kalas isn't acting too angsty, his sarcastic commentary is quite funny. As the guardian spirit, you can embarrass him a few times, usually ending in an amusing What the Hell, Player?.
Some of the Magnus descriptions are pretty hilarious.
If you choose to, Kalas will try the strange green potion at the School of Magic in Komo Mai. His reaction is priceless. Lampshaded by the girl standing nearby.
Watching the two rival bakers arguing in the middle of the streets of Parnasse. To the point where both are apparently on their hands and knees yelling.
In the Imperial Fortress, you can find a set of bathroom stalls. The one on the far left has an Imperial soldier reading a dirty magazine. He takes a few seconds to notice you, then freaks out and tries to kill you. Curb-Stomp Battle ensues, as he's incredibly weak.
Gibari's idea of eating his way through the candy house. Made even better by the rest of the party's reactions which are along the line of "Ew no." and "Go ahead be my guest." Followed by a scene of Gibari actually following through with his plan single handed and regretting it.
King Ladekahn's flustered reaction to finding out Xelha is secretly a queen.
When the group arrives in Mizuti's home and meets Koh and Kay, her parents and Kay calls Mizuti out on insisting upon the "Great" title.
Kay: Mizuti...you're not calling yourself "Great" again, are you?
Similar to the example mentioned above, there are several points in Origins where you can embarrass or anger Sagi by picking the wrong answer.
Listening to Guillo complain about the children in Azha is priceless.
Guillo: Sagi, would you mind getting these moppets off me? They're heavy. Kid: Play with us, puppet! Play! PLAY! Guillo: Blasted parasites! Get off me if you don't want to be eaten! Kid: Yay! Eat me first! Guillo: *sigh* Sagi, have you made up your mind yet? I'm outnumbered...
Milly's reactions to Lolo's advances on Sagi. Hell, pretty much anything with Lolo could qualify.
The 'Love Quadrangle' conversation after leaving Anuenue.
Milly: Assuming you're counting me - there's me, Lolo, and Sagi...who's the fourth?